Abstracts

Rationale: The long-term seizure outcome of epilepsy surgery is not well characterised. In some series longer follow-up has been associated with poorer seizure outcomes. Also, the studies are often cross-sectional making comparisons with shorter follow-up difficult. This study aims at furthering the knowledge about long-term outcome of resective epilepsy surgery. Methods: The Swedish National Epilepsy Register provides population-based data since it has national coverage and the register encompasses data on all patients operated in Sweden since 1990. Long-term prospective and longitudinal follow-up of all patients 5 and 10 years after surgery was initiated in 2005. Patients operated 1995-97 and 2000-2002, respectively, underwent a semi-structured telephone interview 2005-2007, addressing the present seizure situation and changes since the 2-year follow-up, social situation, AED medication and driving. Long-term seizure outcome is here reported for the sum of patients having undergone 5 and 10 year follow-up. Results: The patient cohort consisted of 347 patients, 114 of whom were children (≤18 years) at surgery (33%). 241 of the patients (69% of the total, 47% of the children and 80% of the adults) underwent temporal lobe resection (TLR), while the remaining 106 had various extratemporal resections (XTLR). At the 5 and 10-year follow-up (concerning 159 and 188 patients respectively), 34 patients were not eligible due to reoperation during the period, 14 patients had died and 21 patients were lost to follow-up. Of the remaining 278 patients 163 (59%) were seizure free at long-term follow-up, 45 of the children (52%) versus 118 of the adults (62%). These proportions of seizure free patients compare well with the two-year follow-up at which 52% of all children and 57% of all adults were seizure free. After TLR 23/38 children (61%) were long-term seizure free versus 97/154 adults (63%) compared to 61% and 63% respectively at the two-year follow-up. After XTLR 22/49 children were long-term seizure free (45%) versus 21/37 of the adults (57%) compared to 40% and 46% at the two-year follow-up. Conclusions: In this study of seizure outcome 5 and 10 years after resective epilepsy surgery the seizure free rates are similar to the 2-year follow-up and higher for TLR. For patients the probability of obtaining long-term seizure freedom is an important issue in the decision to accept the irrevocable treatment option of resective epilepsy surgery.